{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-78408", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-08-24T14:40:14.511Z", "datePublished": "2026-09-02T15:05:33.555Z", "dateUpdated": "2026-09-02T15:05:33.555Z"}, "containers": {"cna": {"title": "Util-linux: util-linux: nsenter --join-cgroup leaks root cgroup migration authority", "metrics": [{"other": {"content": {"value": "Important", "namespace": "https://access.redhat.com/security/updates/classification/"}, "type": "Red Hat severity rating"}}, {"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.9, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:H", "version": "3.1"}, "format": "CVSS"}], "descriptions": [{"lang": "en", "value": "The nsenter --join-cgroup option opens the target cgroup.procs file as root and leaves that file descriptor open across later namespace and credential changes and across execve(). Because the kernel checks later cgroup migrations using the credentials from the original open, a program run in an attacker-controlled target can inherit root's ability to move host processes between cgroups. After a privileged operator uses --join-cgroup against that target, an unprivileged user can migrate and terminate unrelated root processes."}], "affected": [{"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 10", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "util-linux", "defaultStatus": "affected", "cpes": ["cpe:/o:redhat:enterprise_linux:10"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 7", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "util-linux", "defaultStatus": "unaffected", "cpes": ["cpe:/o:redhat:enterprise_linux:7"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "util-linux", "defaultStatus": "unaffected", "cpes": ["cpe:/o:redhat:enterprise_linux:8"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "rhel8/flatpak-runtime", "defaultStatus": "unaffected", "cpes": ["cpe:/o:redhat:enterprise_linux:9"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "rhel8/flatpak-sdk", "defaultStatus": "unaffected", "cpes": ["cpe:/o:redhat:enterprise_linux:9"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "util-linux", "defaultStatus": "unaffected", "cpes": ["cpe:/o:redhat:enterprise_linux:9"]}, {"vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "util-linux", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:hummingbird:1"]}, {"vendor": "Red Hat", "product": "Red Hat OpenShift Container Platform 4", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "rhcos", "defaultStatus": "unaffected", "cpes": ["cpe:/a:redhat:openshift:4"]}], "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-78408", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2522497", "name": "RHBZ#2522497", "tags": ["issue-tracking", "x_refsource_REDHAT"]}, {"url": "https://github.com/util-linux/util-linux/security/advisories/GHSA-55fx-f4gg-cfhj"}], "datePublic": "2026-09-02T00:00:00.000Z", "problemTypes": [{"descriptions": [{"cweId": "CWE-775", "description": "Missing Release of File Descriptor or Handle after Effective Lifetime", "lang": "en", "type": "CWE"}]}], "x_redhatCweChain": "CWE-775: Missing Release of File Descriptor or Handle after Effective Lifetime", "workarounds": [{"lang": "en", "value": "Upgrade to util-linux v2.41.6, v2.42.3, or later. Until a fix is applied, do not run nsenter --join-cgroup (including nsenter --target PID --all --join-cgroup) against untrusted processes or namespaces. The fix closes the cgroup.procs descriptor immediately after joining, and opens it with O_CLOEXEC."}], "timeline": [{"lang": "en", "time": "2026-07-26T09:22:21.000Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-09-02T00:00:00.000Z", "value": "Made public."}], "credits": [{"lang": "en", "value": "Red Hat would like to thank Andreas Gabriel Berbescu (Independent Security Researcher) for reporting this issue."}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-09-02T15:05:33.555Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}}}

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